Impact of illness and variables associated with functional impairment in Chinese patients with psoriatic arthritis

To assess the impact of disease and functional outcomes in Chinese patients with psoriatic arthritis (PsA) and to identify variables associated with poor functional outcomes.

A cross sectional study performed in 80 consecutive patients with PsA from a single center. Functional outcomes were assessed by the Health Assessment Questionnaire (HAQ) and the Bath Ankylosing Spondylitis Functional Index (BASFI). Clinical variables included social-demographic characteristics and clinical features. Linear regression analyses were performed to identify variables associated with functional impairment.

Thirty-six men and 44 women with mean (+/-SD) age and duration of arthritis of 48.6 (+/-13.0) and 10.2 (+/-6.9) years were studied. One-third reported PsA related unemployment and change in job nature. Another third experienced a reduction of income due to PsA. The median (IQR) HAQ and BASFI were 0.44 (1.09) and 2.1 (4.38). These functional scores correlated highly with each other and with the patient's perception of health, but correlated only moderately or poorly with other disease activity variables. Multivariate analysis identified higher damaged joint count, poorer patients' perception of health, poor socioeconomic factor and higher CRP as factors associated with higher HAQ. Higher back pain score; higher CRP, higher damaged joint count and poor socioeconomic factor were associated with BASFI.

PsA in Chinese subjects has had significant social-economic impact. Joint damage was found to be associated with functional impairment.